NAME

SYNOPSIS

DESCRIPTION

Compares the files in the working tree and the index. When paths
are specified, compares only those named paths. Otherwise all
entries in the index are compared. The output format is the
same as for git diff-index and git diff-tree.

OPTIONS

-p

-u

--patch

Generate patch (see section on generating patches).
{git-diff? This is the default.}

-s

--no-patch

Suppress diff output. Useful for commands like git show that
show the patch by default, or to cancel the effect of --patch.

This algorithm extends the patience algorithm to "support
low-occurrence common elements".

For instance, if you configured diff.algorithm variable to a
non-default value and want to use the default one, then you
have to use --diff-algorithm=default option.

--stat[=<width>[,<name-width>[,<count>]]]

Generate a diffstat. By default, as much space as necessary
will be used for the filename part, and the rest for the graph
part. Maximum width defaults to terminal width, or 80 columns
if not connected to a terminal, and can be overridden by
<width>. The width of the filename part can be limited by
giving another width <name-width> after a comma. The width
of the graph part can be limited by using
--stat-graph-width=<width> (affects all commands generating
a stat graph) or by setting diff.statGraphWidth=<width>
(does not affect git format-patch).
By giving a third parameter <count>, you can limit the
output to the first <count> lines, followed by ... if
there are more.

These parameters can also be set individually with --stat-width=<width>,
--stat-name-width=<name-width> and --stat-count=<count>.

--numstat

Similar to --stat, but shows number of added and
deleted lines in decimal notation and pathname without
abbreviation, to make it more machine friendly. For
binary files, outputs two - instead of saying
0 0.

--shortstat

Output only the last line of the --stat format containing total
number of modified files, as well as number of added and deleted
lines.

--dirstat[=<param1,param2,…>]

Output the distribution of relative amount of changes for each
sub-directory. The behavior of --dirstat can be customized by
passing it a comma separated list of parameters.
The defaults are controlled by the diff.dirstat configuration
variable (see git-config[1]).
The following parameters are available:

changes

Compute the dirstat numbers by counting the lines that have been
removed from the source, or added to the destination. This ignores
the amount of pure code movements within a file. In other words,
rearranging lines in a file is not counted as much as other changes.
This is the default behavior when no parameter is given.

lines

Compute the dirstat numbers by doing the regular line-based diff
analysis, and summing the removed/added line counts. (For binary
files, count 64-byte chunks instead, since binary files have no
natural concept of lines). This is a more expensive --dirstat
behavior than the changes behavior, but it does count rearranged
lines within a file as much as other changes. The resulting output
is consistent with what you get from the other --*stat options.

files

Compute the dirstat numbers by counting the number of files changed.
Each changed file counts equally in the dirstat analysis. This is
the computationally cheapest --dirstat behavior, since it does
not have to look at the file contents at all.

cumulative

Count changes in a child directory for the parent directory as well.
Note that when using cumulative, the sum of the percentages
reported may exceed 100%. The default (non-cumulative) behavior can
be specified with the noncumulative parameter.

<limit>

An integer parameter specifies a cut-off percent (3% by default).
Directories contributing less than this percentage of the changes
are not shown in the output.

Example: The following will count changed files, while ignoring
directories with less than 10% of the total amount of changed files,
and accumulating child directory counts in the parent directories:
--dirstat=files,10,cumulative.

--summary

Output a condensed summary of extended header information
such as creations, renames and mode changes.

--patch-with-stat

Synonym for -p --stat.

-z

When --raw, --numstat, --name-only or --name-status has been
given, do not munge pathnames and use NULs as output field terminators.

Without this option, each pathname output will have TAB, LF, double quotes,
and backslash characters replaced with \t, \n, \", and \\,
respectively, and the pathname will be enclosed in double quotes if
any of those replacements occurred.

--name-only

Show only names of changed files.

--name-status

Show only names and status of changed files. See the description
of the --diff-filter option on what the status letters mean.

--submodule[=<format>]

Specify how differences in submodules are shown. When --submodule
or --submodule=log is given, the log format is used. This format lists
the commits in the range like git-submodule[1]summary does.
Omitting the --submodule option or specifying --submodule=short,
uses the short format. This format just shows the names of the commits
at the beginning and end of the range. Can be tweaked via the
diff.submodule configuration variable.

--color[=<when>]

Show colored diff.
--color (i.e. without =<when>) is the same as --color=always.
<when> can be one of always, never, or auto.

--no-color

Turn off colored diff.
It is the same as --color=never.

--word-diff[=<mode>]

Show a word diff, using the <mode> to delimit changed words.
By default, words are delimited by whitespace; see
--word-diff-regex below. The <mode> defaults to plain, and
must be one of:

color

Highlight changed words using only colors. Implies --color.

plain

Show words as [-removed-] and {+added+}. Makes no
attempts to escape the delimiters if they appear in the input,
so the output may be ambiguous.

porcelain

Use a special line-based format intended for script
consumption. Added/removed/unchanged runs are printed in the
usual unified diff format, starting with a +/-/` `
character at the beginning of the line and extending to the
end of the line. Newlines in the input are represented by a
tilde ~ on a line of its own.

none

Disable word diff again.

Note that despite the name of the first mode, color is used to
highlight the changed parts in all modes if enabled.

--word-diff-regex=<regex>

Use <regex> to decide what a word is, instead of considering
runs of non-whitespace to be a word. Also implies
--word-diff unless it was already enabled.

Every non-overlapping match of the
<regex> is considered a word. Anything between these matches is
considered whitespace and ignored(!) for the purposes of finding
differences. You may want to append |[^[:space:]] to your regular
expression to make sure that it matches all non-whitespace characters.
A match that contains a newline is silently truncated(!) at the
newline.

The regex can also be set via a diff driver or configuration option, see
gitattributes[1] or git-config[1]. Giving it explicitly
overrides any diff driver or configuration setting. Diff drivers
override configuration settings.

--color-words[=<regex>]

Equivalent to --word-diff=color plus (if a regex was
specified) --word-diff-regex=<regex>.

--no-renames

Turn off rename detection, even when the configuration
file gives the default to do so.

--check

Warn if changes introduce whitespace errors. What are
considered whitespace errors is controlled by core.whitespace
configuration. By default, trailing whitespaces (including
lines that solely consist of whitespaces) and a space character
that is immediately followed by a tab character inside the
initial indent of the line are considered whitespace errors.
Exits with non-zero status if problems are found. Not compatible
with --exit-code.

--full-index

Instead of the first handful of characters, show the full
pre- and post-image blob object names on the "index"
line when generating patch format output.

--binary

In addition to --full-index, output a binary diff that
can be applied with git-apply.

--abbrev[=<n>]

Instead of showing the full 40-byte hexadecimal object
name in diff-raw format output and diff-tree header
lines, show only a partial prefix. This is
independent of the --full-index option above, which controls
the diff-patch output format. Non default number of
digits can be specified with --abbrev=<n>.

-B[<n>][/<m>]

--break-rewrites[=[<n>][/<m>]]

Break complete rewrite changes into pairs of delete and
create. This serves two purposes:

It affects the way a change that amounts to a total rewrite of a file
not as a series of deletion and insertion mixed together with a very
few lines that happen to match textually as the context, but as a
single deletion of everything old followed by a single insertion of
everything new, and the number m controls this aspect of the -B
option (defaults to 60%). -B/70% specifies that less than 30% of the
original should remain in the result for Git to consider it a total
rewrite (i.e. otherwise the resulting patch will be a series of
deletion and insertion mixed together with context lines).

When used with -M, a totally-rewritten file is also considered as the
source of a rename (usually -M only considers a file that disappeared
as the source of a rename), and the number n controls this aspect of
the -B option (defaults to 50%). -B20% specifies that a change with
addition and deletion compared to 20% or more of the file’s size are
eligible for being picked up as a possible source of a rename to
another file.

-M[<n>]

--find-renames[=<n>]

Detect renames.
If n is specified, it is a threshold on the similarity
index (i.e. amount of addition/deletions compared to the
file’s size). For example, -M90% means Git should consider a
delete/add pair to be a rename if more than 90% of the file
hasn’t changed. Without a % sign, the number is to be read as
a fraction, with a decimal point before it. I.e., -M5 becomes
0.5, and is thus the same as -M50%. Similarly, -M05 is
the same as -M5%. To limit detection to exact renames, use
-M100%. The default similarity index is 50%.

-C[<n>]

--find-copies[=<n>]

Detect copies as well as renames. See also --find-copies-harder.
If n is specified, it has the same meaning as for -M<n>.

--find-copies-harder

For performance reasons, by default, -C option finds copies only
if the original file of the copy was modified in the same
changeset. This flag makes the command
inspect unmodified files as candidates for the source of
copy. This is a very expensive operation for large
projects, so use it with caution. Giving more than one
-C option has the same effect.

-D

--irreversible-delete

Omit the preimage for deletes, i.e. print only the header but not
the diff between the preimage and /dev/null. The resulting patch
is not meant to be applied with patch or git apply; this is
solely for people who want to just concentrate on reviewing the
text after the change. In addition, the output obviously lack
enough information to apply such a patch in reverse, even manually,
hence the name of the option.

When used together with -B, omit also the preimage in the deletion part
of a delete/create pair.

-l<num>

The -M and -C options require O(n^2) processing time where n
is the number of potential rename/copy targets. This
option prevents rename/copy detection from running if
the number of rename/copy targets exceeds the specified
number.

--diff-filter=[(A|C|D|M|R|T|U|X|B)…[*]]

Select only files that are Added (A), Copied (C),
Deleted (D), Modified (M), Renamed (R), have their
type (i.e. regular file, symlink, submodule, …) changed (T),
are Unmerged (U), are
Unknown (X), or have had their pairing Broken (B).
Any combination of the filter characters (including none) can be used.
When * (All-or-none) is added to the combination, all
paths are selected if there is any file that matches
other criteria in the comparison; if there is no file
that matches other criteria, nothing is selected.

-S<string>

Look for differences that change the number of occurrences of
the specified string (i.e. addition/deletion) in a file.
Intended for the scripter’s use.

It is useful when you’re looking for an exact block of code (like a
struct), and want to know the history of that block since it first
came into being: use the feature iteratively to feed the interesting
block in the preimage back into -S, and keep going until you get the
very first version of the block.

When -S or -G finds a change, show all the changes in that
changeset, not just the files that contain the change
in <string>.

--pickaxe-regex

Treat the <string> given to -S as an extended POSIX regular
expression to match.

-O<orderfile>

Output the patch in the order specified in the
<orderfile>, which has one shell glob pattern per line.
This overrides the diff.orderfile configuration variable
(see git-config[1]). To cancel diff.orderfile,
use -O/dev/null.

-R

Swap two inputs; that is, show differences from index or
on-disk file to tree contents.

--relative[=<path>]

When run from a subdirectory of the project, it can be
told to exclude changes outside the directory and show
pathnames relative to it with this option. When you are
not in a subdirectory (e.g. in a bare repository), you
can name which subdirectory to make the output relative
to by giving a <path> as an argument.

-a

--text

Treat all files as text.

--ignore-space-at-eol

Ignore changes in whitespace at EOL.

-b

--ignore-space-change

Ignore changes in amount of whitespace. This ignores whitespace
at line end, and considers all other sequences of one or
more whitespace characters to be equivalent.

-w

--ignore-all-space

Ignore whitespace when comparing lines. This ignores
differences even if one line has whitespace where the other
line has none.

--ignore-blank-lines

Ignore changes whose lines are all blank.

--inter-hunk-context=<lines>

Show the context between diff hunks, up to the specified number
of lines, thereby fusing hunks that are close to each other.

-W

--function-context

Show whole surrounding functions of changes.

--exit-code

Make the program exit with codes similar to diff(1).
That is, it exits with 1 if there were differences and
0 means no differences.

--quiet

Disable all output of the program. Implies --exit-code.

--ext-diff

Allow an external diff helper to be executed. If you set an
external diff driver with gitattributes[5], you need
to use this option with git-log[1] and friends.

--no-ext-diff

Disallow external diff drivers.

--textconv

--no-textconv

Allow (or disallow) external text conversion filters to be run
when comparing binary files. See gitattributes[5] for
details. Because textconv filters are typically a one-way
conversion, the resulting diff is suitable for human
consumption, but cannot be applied. For this reason, textconv
filters are enabled by default only for git-diff[1] and
git-log[1], but not for git-format-patch[1] or
diff plumbing commands.

--ignore-submodules[=<when>]

Ignore changes to submodules in the diff generation. <when> can be
either "none", "untracked", "dirty" or "all", which is the default.
Using "none" will consider the submodule modified when it either contains
untracked or modified files or its HEAD differs from the commit recorded
in the superproject and can be used to override any settings of the
ignore option in git-config[1] or gitmodules[5]. When
"untracked" is used submodules are not considered dirty when they only
contain untracked content (but they are still scanned for modified
content). Using "dirty" ignores all changes to the work tree of submodules,
only changes to the commits stored in the superproject are shown (this was
the behavior until 1.7.0). Using "all" hides all changes to submodules.

--src-prefix=<prefix>

Show the given source prefix instead of "a/".

--dst-prefix=<prefix>

Show the given destination prefix instead of "b/".

--no-prefix

Do not show any source or destination prefix.

For more detailed explanation on these common options, see also
gitdiffcore[7].

-1 --base

-2 --ours

-3 --theirs

-0

Diff against the "base" version, "our branch" or "their
branch" respectively. With these options, diffs for
merged entries are not shown.

The default is to diff against our branch (-2) and the
cleanly resolved paths. The option -0 can be given to
omit diff output for unmerged entries and just show "Unmerged".

-c

--cc

This compares stage 2 (our branch), stage 3 (their
branch) and the working tree file and outputs a combined
diff, similar to the way diff-tree shows a merge
commit with these flags.

-q

Remain silent even on nonexistent files

Raw output format

The raw output format from "git-diff-index", "git-diff-tree",
"git-diff-files" and "git diff --raw" are very similar.

These commands all compare two sets of things; what is
compared differs:

git-diff-index <tree-ish>

compares the <tree-ish> and the files on the filesystem.

git-diff-index --cached <tree-ish>

compares the <tree-ish> and the index.

git-diff-tree [-r] <tree-ish-1> <tree-ish-2> [<pattern>…]

compares the trees named by the two arguments.

git-diff-files [<pattern>…]

compares the index and the files on the filesystem.

The "git-diff-tree" command begins its output by printing the hash of
what is being compared. After that, all the commands print one output
line per changed file.

U: file is unmerged (you must complete the merge before it can
be committed)

X: "unknown" change type (most probably a bug, please report it)

Status letters C and R are always followed by a score (denoting the
percentage of similarity between the source and target of the move or
copy). Status letter M may be followed by a score (denoting the
percentage of dissimilarity) for file rewrites.

<sha1> is shown as all 0’s if a file is new on the filesystem
and it is out of sync with the index.

Example:

:100644 100644 5be4a4...... 000000...... M file.c

When -z option is not used, TAB, LF, and backslash characters
in pathnames are represented as \t, \n, and \\,
respectively.

diff format for merges

"git-diff-tree", "git-diff-files" and "git-diff --raw"
can take -c or --cc option
to generate diff output also for merge commits. The output differs
from the format described above in the following way:

there is a colon for each parent

there are more "src" modes and "src" sha1

status is concatenated status characters for each parent

no optional "score" number

single path, only for "dst"

Example:

::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM describe.c

Note that combined diff lists only files which were modified from
all parents.

Generating patches with -p

When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
with a -p option, "git diff" without the --raw option, or
"git log" with the "-p" option, they
do not produce the output described above; instead they produce a
patch file. You can customize the creation of such patches via the
GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables.

What the -p option produces is slightly different from the traditional
diff format:

It is preceded with a "git diff" header that looks like this:

diff --git a/file1 b/file2

The a/ and b/ filenames are the same unless rename/copy is
involved. Especially, even for a creation or a deletion,
/dev/null is not used in place of the a/ or b/ filenames.

When rename/copy is involved, file1 and file2 show the
name of the source file of the rename/copy and the name of
the file that rename/copy produces, respectively.

File modes are printed as 6-digit octal numbers including the file type
and file permission bits.

Path names in extended headers do not include the a/ and b/ prefixes.

The similarity index is the percentage of unchanged lines, and
the dissimilarity index is the percentage of changed lines. It
is a rounded down integer, followed by a percent sign. The
similarity index value of 100% is thus reserved for two equal
files, while 100% dissimilarity means that no line from the old
file made it into the new one.

The index line includes the SHA-1 checksum before and after the change.
The <mode> is included if the file mode does not change; otherwise,
separate lines indicate the old and the new mode.

TAB, LF, double quote and backslash characters in pathnames
are represented as \t, \n, \" and \\, respectively.
If there is need for such substitution then the whole
pathname is put in double quotes.

All the file1 files in the output refer to files before the
commit, and all the file2 files refer to files after the commit.
It is incorrect to apply each change to each file sequentially. For
example, this patch will swap a and b:

diff --git a/a b/b
rename from a
rename to b
diff --git a/b b/a
rename from b
rename to a

combined diff format

Any diff-generating command can take the -c or --cc option to
produce a combined diff when showing a merge. This is the default
format when showing merges with git-diff[1] or
git-show[1]. Note also that you can give the ‘-m’ option to any
of these commands to force generation of diffs with individual parents
of a merge.

The mode <mode>,<mode>..<mode> line appears only if at least one of
the <mode> is different from the rest. Extended headers with
information about detected contents movement (renames and
copying detection) are designed to work with diff of two
<tree-ish> and are not used by combined diff format.

It is followed by two-line from-file/to-file header

--- a/file
+++ b/file

Similar to two-line header for traditional unified diff
format, /dev/null is used to signal created or deleted
files.

Chunk header format is modified to prevent people from
accidentally feeding it to patch -p1. Combined diff format
was created for review of merge commit changes, and was not
meant for apply. The change is similar to the change in the
extended index header:

@@@ <from-file-range> <from-file-range> <to-file-range> @@@

There are (number of parents + 1) @ characters in the chunk
header for combined diff format.

Unlike the traditional unified diff format, which shows two
files A and B with a single column that has - (minus — appears in A but removed in B), + (plus — missing in A but
added to B), or " " (space — unchanged) prefix, this format
compares two or more files file1, file2,… with one file X, and
shows how X differs from each of fileN. One column for each of
fileN is prepended to the output line to note how X’s line is
different from it.

A - character in the column N means that the line appears in
fileN but it does not appear in the result. A + character
in the column N means that the line appears in the result,
and fileN does not have that line (in other words, the line was
added, from the point of view of that parent).

In the above example output, the function signature was changed
from both files (hence two - removals from both file1 and
file2, plus ++ to mean one line that was added does not appear
in either file1 or file2). Also eight other lines are the same
from file1 but do not appear in file2 (hence prefixed with +).

When shown by git diff-tree -c, it compares the parents of a
merge commit with the merge result (i.e. file1..fileN are the
parents). When shown by git diff-files -c, it compares the
two unresolved merge parents with the working tree file
(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
"their version").

other diff formats

The --summary option describes newly added, deleted, renamed and
copied files. The --stat option adds diffstat(1) graph to the
output. These options can be combined with other options, such as
-p, and are meant for human consumption.

When showing a change that involves a rename or a copy, --stat output
formats the pathnames compactly by combining common prefix and suffix of
the pathnames. For example, a change that moves arch/i386/Makefile to
arch/x86/Makefile while modifying 4 lines will be shown like this:

arch/{i386 => x86}/Makefile | 4 +--

The --numstat option gives the diffstat(1) information but is designed
for easier machine consumption. An entry in --numstat output looks
like this:

1 2 README
3 1 arch/{i386 => x86}/Makefile

That is, from left to right:

the number of added lines;

a tab;

the number of deleted lines;

a tab;

pathname (possibly with rename/copy information);

a newline.

When -z output option is in effect, the output is formatted this way:

1 2 README NUL
3 1 NUL arch/i386/Makefile NUL arch/x86/Makefile NUL

That is:

the number of added lines;

a tab;

the number of deleted lines;

a tab;

a NUL (only exists if renamed/copied);

pathname in preimage;

a NUL (only exists if renamed/copied);

pathname in postimage (only exists if renamed/copied);

a NUL.

The extra NUL before the preimage path in renamed case is to allow
scripts that read the output to tell if the current record being read is
a single-path record or a rename/copy record without reading ahead.
After reading added and deleted lines, reading up to NUL would yield
the pathname, but if that is NUL, the record will show two paths.